:root {
  color-scheme: light;
  --bg: #f6f4ef;
  --surface: #ffffff;
  --ink: #202124;
  --muted: #6a6f73;
  --line: #d9d5ca;
  --accent: #245c53;
  --accent-ink: #ffffff;
  --warning: #b04436;
  --focus: #f0b44d;
  --region-0: #f4c7ab;
  --region-1: #f0dc87;
  --region-2: #a7d8b6;
  --region-3: #93c9d5;
  --region-4: #c5b6e3;
  --region-5: #f3a7b6;
  --region-6: #bfd4a3;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.5;
  overflow-x: hidden;
}

button,
input {
  font: inherit;
}

button {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  min-height: 42px;
  padding: 0 14px;
  cursor: pointer;
}

button:hover {
  border-color: var(--accent);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

button:disabled:hover {
  border-color: var(--line);
}

button:focus-visible,
input:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--focus), transparent 35%);
  outline-offset: 2px;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-bottom: 1px solid var(--line);
  background: rgba(246, 244, 239, 0.94);
  padding: 12px clamp(16px, 4vw, 48px);
  backdrop-filter: blur(10px);
}

.brand,
.nav a {
  color: var(--ink);
  text-decoration: none;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 760;
}

.brand-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-ink);
  font-size: 0.78rem;
  letter-spacing: 0;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.nav a {
  border-radius: 8px;
  padding: 8px 10px;
  color: var(--muted);
  font-size: 0.94rem;
}

.nav a:hover {
  background: rgba(36, 92, 83, 0.08);
  color: var(--ink);
}

.section-shell {
  width: calc(100% - 32px);
  max-width: 1120px;
  margin: 0 auto;
}

.play-section,
.tool-section,
.rules-section,
.seo-section,
.faq-section,
.internal-links-section {
  padding: clamp(24px, 5vw, 56px) 0;
}

.play-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 310px;
  gap: 20px;
  align-items: start;
}

.game-column,
.side-panel,
.calculator-panel {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 16px 40px rgba(32, 33, 36, 0.08);
}

.game-column {
  padding: clamp(16px, 3vw, 28px);
}

.game-head {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 18px;
}

.eyebrow {
  margin: 0 0 3px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2 {
  margin: 0;
  letter-spacing: 0;
  line-height: 1.06;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
}

h2 {
  font-size: clamp(1.7rem, 4vw, 2.6rem);
}

.lede {
  max-width: 580px;
  color: var(--muted);
}

.game-intro {
  max-width: 560px;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 1rem;
}

.proof-points {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  max-width: 560px;
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.proof-points li {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfaf7;
  padding: 7px 10px;
  color: var(--ink);
  font-size: 0.9rem;
  font-weight: 760;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(64px, 1fr));
  gap: 8px;
}

.stats div,
.metric-strip div {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  text-align: center;
}

.stats span,
.metric-strip strong {
  display: block;
  font-size: 1.06rem;
  font-weight: 800;
}

.stats small,
.metric-strip span {
  display: block;
  color: var(--muted);
  font-size: 0.75rem;
}

.board-wrap {
  display: grid;
  width: 100%;
  max-width: 100%;
  place-items: center;
  overflow: hidden;
}

.board-stage {
  position: relative;
  width: 100%;
  max-width: 560px;
  aspect-ratio: 1;
}

.board {
  display: grid;
  width: 100%;
  max-width: none;
  aspect-ratio: 1;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  border: 3px solid #2f3336;
  background: #2f3336;
  gap: 2px;
  touch-action: manipulation;
}

.cell {
  position: relative;
  display: grid;
  min-width: 0;
  min-height: 0;
  place-items: center;
  border: 0;
  border-radius: 0;
  color: #1e2527;
  font-size: clamp(1.3rem, 5.5vw, 2.4rem);
  font-weight: 900;
  line-height: 1;
  padding: 0;
}

.cell:disabled {
  cursor: default;
  opacity: 1;
}

.start-overlay {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  border: 3px solid #2f3336;
  background: rgba(246, 244, 239, 0.92);
  padding: clamp(14px, 4vw, 28px);
  backdrop-filter: blur(6px);
}

.start-overlay[hidden] {
  display: none;
}

.start-card {
  width: min(100%, 360px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.94);
  padding: clamp(16px, 4vw, 24px);
  text-align: center;
  box-shadow: 0 18px 44px rgba(32, 33, 36, 0.16);
}

.start-card h2 {
  font-size: clamp(1.35rem, 4vw, 2.2rem);
}

.start-card p:not(.eyebrow) {
  margin: 10px 0 16px;
  color: var(--muted);
}

.start-card .primary {
  width: 100%;
}

.cell[data-region="0"] {
  background: var(--region-0);
}

.cell[data-region="1"] {
  background: var(--region-1);
}

.cell[data-region="2"] {
  background: var(--region-2);
}

.cell[data-region="3"] {
  background: var(--region-3);
}

.cell[data-region="4"] {
  background: var(--region-4);
}

.cell[data-region="5"] {
  background: var(--region-5);
}

.cell[data-region="6"] {
  background: var(--region-6);
}

.cell.blocked::after {
  content: "";
  width: 42%;
  height: 42%;
  border-radius: 50%;
  background: rgba(32, 33, 36, 0.25);
}

.cell.star {
  color: #1d2124;
}

.cell.error {
  box-shadow: inset 0 0 0 4px var(--warning);
}

.cell.hint {
  box-shadow: inset 0 0 0 4px #ffffff, inset 0 0 0 8px var(--focus);
}

.status {
  min-height: 26px;
  margin: 14px 0 0;
  color: var(--muted);
  font-weight: 650;
}

.status.success {
  color: var(--accent);
}

.status.error {
  color: var(--warning);
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.primary {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--accent-ink);
}

.side-panel {
  padding: 18px;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.share-preview {
  min-height: 116px;
  margin: 16px 0;
  border: 1px dashed var(--line);
  border-radius: 8px;
  background: #fbfaf7;
  padding: 14px;
  color: var(--muted);
  overflow-wrap: anywhere;
  white-space: pre-line;
}

.quick-rules {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  margin: 0 0 16px;
  padding: 14px 0;
}

.quick-rules h2 {
  margin: 0 0 8px;
  font-size: 1rem;
}

.quick-rules ul {
  display: grid;
  gap: 6px;
  margin: 0;
  padding-left: 20px;
  color: var(--ink);
}

.quick-rules p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 0.94rem;
}

.mini-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.tool-section {
  background: #eef3f0;
}

.tool-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1.15fr);
  gap: 28px;
  align-items: start;
}

.calculator-panel {
  padding: clamp(16px, 3vw, 24px);
}

.combo-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.combo-form label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-weight: 720;
}

.combo-form input[type="number"] {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 12px;
  color: var(--ink);
}

.check-label {
  grid-column: 1 / -1;
  display: flex !important;
  grid-template-columns: none !important;
  align-items: center;
  gap: 9px !important;
}

.check-label input {
  width: 18px;
  height: 18px;
}

.digits {
  display: grid;
  grid-template-columns: repeat(9, minmax(0, 1fr));
  gap: 6px;
  margin: 14px 0;
}

.digit-toggle {
  min-width: 0;
  padding: 0;
}

.digit-toggle.active {
  border-color: var(--accent);
  background: rgba(36, 92, 83, 0.12);
  color: var(--accent);
  font-weight: 800;
}

.result-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-top: 1px solid var(--line);
  padding-top: 14px;
}

.combo-results {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  min-height: 72px;
  margin-top: 12px;
}

.combo-pill {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfaf7;
  padding: 7px 10px;
  font-variant-numeric: tabular-nums;
}

.rules-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.6fr) minmax(280px, 1fr);
  gap: 24px;
}

.rules-list {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.rules-list li {
  border-left: 4px solid var(--accent);
  background: rgba(255, 255, 255, 0.72);
  padding: 12px 14px;
}

.seo-section {
  background: #fbfaf7;
}

.seo-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.seo-grid article,
.faq-list details {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  padding: clamp(16px, 3vw, 22px);
}

.seo-grid p,
.faq-list p {
  color: var(--muted);
}

.faq-list {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.faq-list summary {
  cursor: pointer;
  font-weight: 800;
}

.faq-list p {
  margin-bottom: 0;
}

.internal-links-section {
  background: #eef3f0;
}

.internal-links {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.internal-links a {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  padding: 14px 16px;
  text-decoration: none;
  font-weight: 800;
}

.internal-links a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 20px 0;
  color: var(--muted);
}

.site-footer .section-shell {
  display: flex;
  justify-content: space-between;
  gap: 16px;
}

.site-footer a {
  color: var(--accent);
  text-decoration: none;
}

.content-page {
  padding: clamp(28px, 6vw, 72px) 0;
}

.content-card {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  padding: clamp(18px, 4vw, 34px);
  box-shadow: 0 16px 40px rgba(32, 33, 36, 0.08);
}

.content-card h1 {
  max-width: 860px;
  font-size: clamp(2.1rem, 6vw, 4rem);
}

.content-card h2 {
  margin-top: 28px;
  font-size: clamp(1.35rem, 3vw, 2rem);
}

.content-card p,
.content-card li {
  color: var(--muted);
}

.content-card a {
  color: var(--accent);
  font-weight: 800;
}

.content-card ul,
.content-card ol {
  display: grid;
  gap: 8px;
}

@media (max-width: 840px) {
  .topbar {
    align-items: start;
    flex-direction: column;
  }

  .play-layout,
  .tool-layout,
  .rules-grid,
  .seo-grid,
  .internal-links {
    grid-template-columns: 1fr;
  }

  .game-head {
    flex-direction: column;
  }

  .stats {
    width: 100%;
  }
}

@media (max-width: 520px) {
  .section-shell {
    width: calc(100% - 20px);
  }

  .nav {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    width: 100%;
    gap: 0;
  }

  .nav a {
    flex: 1;
    min-width: 0;
    text-align: center;
  }

  .stats div,
  .metric-strip div {
    padding-right: 6px;
    padding-left: 6px;
  }

  .toolbar,
  .mini-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .toolbar .primary {
    grid-column: 1 / -1;
  }

  .digits {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}